It is known that some memory cards have an USB interface (USB stands for universal serial bus) or an SD interface (SD stands for secure digital) as well as have a wireless communication interface such as TransferJet or IEEE802.11. Among devices that use memory cards, there are devices which communicate via the USB interface or the SD interface and there are devices which communicate via the wireless communication interface such as TransferJet or IEEE802.11. Each such device can access a storage device (i.e., a device for storing data) installed in the memory card, and can perform reading and writing operations with respect to the data stored in the storage device.
However, if an attempt to write data is performed from a remote location via the wireless communication interface, then there occurs inconsistency between a data cache, which is maintained with respect to the data stored in the memory card and which is maintained in a terminal to which the memory card is connected, and the updated data in the storage device that gets updated due to the writing operation. Consequently, there are times when a mismatch in the contents of the stored data remains unresolved or when a mismatch in the file management information leads to malfunctioning of the file system.